Mythic Package File Format (.UOP)

Mythic Package File Format (.UOP)

[1] Format Header

BYTE  -> 'M'
BYTE  -> 'Y'
BYTE  -> 'P'
BYTE  ->  0
DWORD -> Version
DWORD -> Signature?
QWORD -> Address of the first [2] Block
DWORD -> Max number of files per block
DWORD -> Number of files in this package
BYTE[]-> 0

[2] Block Header

DWORD -> Number of files in this block
QWORD -> Address of the next block

[3] File Header

QWORD -> Address of [4] Data Header
DWORD -> Length of file header
DWORD -> Size of compressed file
DWORD -> Size of decompressed file
QWORD -> File hash
DWORD -> Adler32 of [4a] Data Header in little endian, unknown in Version 5
WORD  -> Compression type (0 - no compression, 1 - zlib)

[4] Data Header (Version 4)

WORD  -> Data type
WORD  -> Offset to data
QWORD -> File time (number of 100-nanosecond intervals since January 1, 1601 UTC)
BYTE  -> (size of compressed file) -> File	

[4] Data Header (Version 5)

BYTE[]-> Metadata used by UO patcher

Pseudocode: [1] Format Header

while ( Address of the next block > 0 )
	[2] File Header

	while ( Max number of files per block )
		[3] File Header
	end

	while ( Number of files in this block )
		[4] Data Header
	end	
end